github.com/xmx/lua@v0.0.0-20230324063450-8a298e091302/opcode.go (about)

     1  package lua
     2  
     3  import "fmt"
     4  
     5  /*
     6    gopherlua uses Lua 5.1.4's opcodes.
     7    Lua 5.1.4 opcodes layout:
     8  
     9            instruction = 32bit(fixed length)
    10  
    11    +---------------------------------------------+
    12    |0-5(6bits)|6-13(8bit)|14-22(9bit)|23-31(9bit)|
    13    |==========+==========+===========+===========|
    14    |  opcode  |    A     |     C     |    B      |
    15    |----------+----------+-----------+-----------|
    16    |  opcode  |    A     |      Bx(unsigned)     |
    17    |----------+----------+-----------+-----------|
    18    |  opcode  |    A     |      sBx(signed)      |
    19    +---------------------------------------------+
    20  */
    21  
    22  const opInvalidInstruction = ^uint32(0)
    23  
    24  const (
    25  	opSizeCode = 6
    26  	opSizeA    = 8
    27  	opSizeB    = 9
    28  	opSizeC    = 9
    29  	opSizeBx   = 18
    30  	opSizesBx  = 18
    31  )
    32  
    33  const (
    34  	opMaxArgsA  = (1 << opSizeA) - 1
    35  	opMaxArgsB  = (1 << opSizeB) - 1
    36  	opMaxArgsC  = (1 << opSizeC) - 1
    37  	opMaxArgBx  = (1 << opSizeBx) - 1
    38  	opMaxArgSbx = opMaxArgBx >> 1
    39  )
    40  
    41  const (
    42  	OP_MOVE     int = iota /*      A B     R(A) := R(B)                            */
    43  	OP_MOVEN               /*      A B     R(A) := R(B); followed by R(C) MOVE ops */
    44  	OP_LOADK               /*     A Bx    R(A) := Kst(Bx)                          */
    45  	OP_LOADBOOL            /*  A B C   R(A) := (Bool)B; if (C) pc++                */
    46  	OP_LOADNIL             /*   A B     R(A) := ... := R(B) := nil                 */
    47  	OP_GETUPVAL            /*  A B     R(A) := UpValue[B]                          */
    48  
    49  	OP_GETGLOBAL  /* A Bx    R(A) := Gbl[Kst(Bx)]                            */
    50  	OP_GETTABLE   /*  A B C   R(A) := R(B)[RK(C)]                             */
    51  	OP_GETTABLEKS /*  A B C   R(A) := R(B)[RK(C)] ; RK(C) is constant string */
    52  
    53  	OP_SETGLOBAL  /* A Bx    Gbl[Kst(Bx)] := R(A)                            */
    54  	OP_SETUPVAL   /*  A B     UpValue[B] := R(A)                              */
    55  	OP_SETTABLE   /*  A B C   R(A)[RK(B)] := RK(C)                            */
    56  	OP_SETTABLEKS /*  A B C   R(A)[RK(B)] := RK(C) ; RK(B) is constant string */
    57  
    58  	OP_NEWTABLE /*  A B C   R(A) := {} (size = BC)                         */
    59  
    60  	OP_SELF /*      A B C   R(A+1) := R(B); R(A) := R(B)[RK(C)]             */
    61  
    62  	OP_ADD /*       A B C   R(A) := RK(B) + RK(C)                           */
    63  	OP_SUB /*       A B C   R(A) := RK(B) - RK(C)                           */
    64  	OP_MUL /*       A B C   R(A) := RK(B) * RK(C)                           */
    65  	OP_DIV /*       A B C   R(A) := RK(B) / RK(C)                           */
    66  	OP_MOD /*       A B C   R(A) := RK(B) % RK(C)                           */
    67  	OP_POW /*       A B C   R(A) := RK(B) ^ RK(C)                           */
    68  	OP_UNM /*       A B     R(A) := -R(B)                                   */
    69  	OP_NOT /*       A B     R(A) := not R(B)                                */
    70  	OP_LEN /*       A B     R(A) := length of R(B)                          */
    71  
    72  	OP_CONCAT /*    A B C   R(A) := R(B).. ... ..R(C)                       */
    73  
    74  	OP_JMP /*       sBx     pc+=sBx                                 */
    75  
    76  	OP_EQ /*        A B C   if ((RK(B) == RK(C)) ~= A) then pc++            */
    77  	OP_LT /*        A B C   if ((RK(B) <  RK(C)) ~= A) then pc++            */
    78  	OP_LE /*        A B C   if ((RK(B) <= RK(C)) ~= A) then pc++            */
    79  
    80  	OP_TEST    /*      A C     if not (R(A) <=> C) then pc++                   */
    81  	OP_TESTSET /*   A B C   if (R(B) <=> C) then R(A) := R(B) else pc++     */
    82  
    83  	OP_CALL     /*      A B C   R(A) ... R(A+C-2) := R(A)(R(A+1) ... R(A+B-1)) */
    84  	OP_TAILCALL /*  A B C   return R(A)(R(A+1) ... R(A+B-1))              */
    85  	OP_RETURN   /*    A B     return R(A) ... R(A+B-2)      (see note)      */
    86  
    87  	OP_FORLOOP /*   A sBx   R(A)+=R(A+2);
    88  	     if R(A) <?= R(A+1) then { pc+=sBx; R(A+3)=R(A) }*/
    89  	OP_FORPREP /*   A sBx   R(A)-=R(A+2); pc+=sBx                           */
    90  
    91  	OP_TFORLOOP /*  A C     R(A+3) ... R(A+3+C) := R(A)(R(A+1) R(A+2));
    92  	    if R(A+3) ~= nil then { pc++; R(A+2)=R(A+3); }  */
    93  	OP_SETLIST /*   A B C   R(A)[(C-1)*FPF+i] := R(A+i) 1 <= i <= B        */
    94  
    95  	OP_CLOSE   /*     A       close all variables in the stack up to (>=) R(A)*/
    96  	OP_CLOSURE /*   A Bx    R(A) := closure(KPROTO[Bx] R(A) ... R(A+n))  */
    97  
    98  	OP_VARARG /*     A B     R(A) R(A+1) ... R(A+B-1) = vararg            */
    99  
   100  	OP_NOP /* NOP */
   101  )
   102  const opCodeMax = OP_NOP
   103  
   104  type opArgMode int
   105  
   106  const (
   107  	opArgModeN opArgMode = iota
   108  	opArgModeU
   109  	opArgModeR
   110  	opArgModeK
   111  )
   112  
   113  type opType int
   114  
   115  const (
   116  	opTypeABC = iota
   117  	opTypeABx
   118  	opTypeASbx
   119  )
   120  
   121  type opProp struct {
   122  	Name     string
   123  	IsTest   bool
   124  	SetRegA  bool
   125  	ModeArgB opArgMode
   126  	ModeArgC opArgMode
   127  	Type     opType
   128  }
   129  
   130  var opProps = []opProp{
   131  	{"MOVE", false, true, opArgModeR, opArgModeN, opTypeABC},
   132  	{"MOVEN", false, true, opArgModeR, opArgModeN, opTypeABC},
   133  	{"LOADK", false, true, opArgModeK, opArgModeN, opTypeABx},
   134  	{"LOADBOOL", false, true, opArgModeU, opArgModeU, opTypeABC},
   135  	{"LOADNIL", false, true, opArgModeR, opArgModeN, opTypeABC},
   136  	{"GETUPVAL", false, true, opArgModeU, opArgModeN, opTypeABC},
   137  	{"GETGLOBAL", false, true, opArgModeK, opArgModeN, opTypeABx},
   138  	{"GETTABLE", false, true, opArgModeR, opArgModeK, opTypeABC},
   139  	{"GETTABLEKS", false, true, opArgModeR, opArgModeK, opTypeABC},
   140  	{"SETGLOBAL", false, false, opArgModeK, opArgModeN, opTypeABx},
   141  	{"SETUPVAL", false, false, opArgModeU, opArgModeN, opTypeABC},
   142  	{"SETTABLE", false, false, opArgModeK, opArgModeK, opTypeABC},
   143  	{"SETTABLEKS", false, false, opArgModeK, opArgModeK, opTypeABC},
   144  	{"NEWTABLE", false, true, opArgModeU, opArgModeU, opTypeABC},
   145  	{"SELF", false, true, opArgModeR, opArgModeK, opTypeABC},
   146  	{"ADD", false, true, opArgModeK, opArgModeK, opTypeABC},
   147  	{"SUB", false, true, opArgModeK, opArgModeK, opTypeABC},
   148  	{"MUL", false, true, opArgModeK, opArgModeK, opTypeABC},
   149  	{"DIV", false, true, opArgModeK, opArgModeK, opTypeABC},
   150  	{"MOD", false, true, opArgModeK, opArgModeK, opTypeABC},
   151  	{"POW", false, true, opArgModeK, opArgModeK, opTypeABC},
   152  	{"UNM", false, true, opArgModeR, opArgModeN, opTypeABC},
   153  	{"NOT", false, true, opArgModeR, opArgModeN, opTypeABC},
   154  	{"LEN", false, true, opArgModeR, opArgModeN, opTypeABC},
   155  	{"CONCAT", false, true, opArgModeR, opArgModeR, opTypeABC},
   156  	{"JMP", false, false, opArgModeR, opArgModeN, opTypeASbx},
   157  	{"EQ", true, false, opArgModeK, opArgModeK, opTypeABC},
   158  	{"LT", true, false, opArgModeK, opArgModeK, opTypeABC},
   159  	{"LE", true, false, opArgModeK, opArgModeK, opTypeABC},
   160  	{"TEST", true, true, opArgModeR, opArgModeU, opTypeABC},
   161  	{"TESTSET", true, true, opArgModeR, opArgModeU, opTypeABC},
   162  	{"CALL", false, true, opArgModeU, opArgModeU, opTypeABC},
   163  	{"TAILCALL", false, true, opArgModeU, opArgModeU, opTypeABC},
   164  	{"RETURN", false, false, opArgModeU, opArgModeN, opTypeABC},
   165  	{"FORLOOP", false, true, opArgModeR, opArgModeN, opTypeASbx},
   166  	{"FORPREP", false, true, opArgModeR, opArgModeN, opTypeASbx},
   167  	{"TFORLOOP", true, false, opArgModeN, opArgModeU, opTypeABC},
   168  	{"SETLIST", false, false, opArgModeU, opArgModeU, opTypeABC},
   169  	{"CLOSE", false, false, opArgModeN, opArgModeN, opTypeABC},
   170  	{"CLOSURE", false, true, opArgModeU, opArgModeN, opTypeABx},
   171  	{"VARARG", false, true, opArgModeU, opArgModeN, opTypeABC},
   172  	{"NOP", false, false, opArgModeR, opArgModeN, opTypeASbx},
   173  }
   174  
   175  func opGetOpCode(inst uint32) int {
   176  	return int(inst >> 26)
   177  }
   178  
   179  func opSetOpCode(inst *uint32, opcode int) {
   180  	*inst = (*inst & 0x3ffffff) | uint32(opcode<<26)
   181  }
   182  
   183  func opGetArgA(inst uint32) int {
   184  	return int(inst>>18) & 0xff
   185  }
   186  
   187  func opSetArgA(inst *uint32, arg int) {
   188  	*inst = (*inst & 0xfc03ffff) | uint32((arg&0xff)<<18)
   189  }
   190  
   191  func opGetArgB(inst uint32) int {
   192  	return int(inst & 0x1ff)
   193  }
   194  
   195  func opSetArgB(inst *uint32, arg int) {
   196  	*inst = (*inst & 0xfffffe00) | uint32(arg&0x1ff)
   197  }
   198  
   199  func opGetArgC(inst uint32) int {
   200  	return int(inst>>9) & 0x1ff
   201  }
   202  
   203  func opSetArgC(inst *uint32, arg int) {
   204  	*inst = (*inst & 0xfffc01ff) | uint32((arg&0x1ff)<<9)
   205  }
   206  
   207  func opGetArgBx(inst uint32) int {
   208  	return int(inst & 0x3ffff)
   209  }
   210  
   211  func opSetArgBx(inst *uint32, arg int) {
   212  	*inst = (*inst & 0xfffc0000) | uint32(arg&0x3ffff)
   213  }
   214  
   215  func opGetArgSbx(inst uint32) int {
   216  	return opGetArgBx(inst) - opMaxArgSbx
   217  }
   218  
   219  func opSetArgSbx(inst *uint32, arg int) {
   220  	opSetArgBx(inst, arg+opMaxArgSbx)
   221  }
   222  
   223  func opCreateABC(op int, a int, b int, c int) uint32 {
   224  	var inst uint32 = 0
   225  	opSetOpCode(&inst, op)
   226  	opSetArgA(&inst, a)
   227  	opSetArgB(&inst, b)
   228  	opSetArgC(&inst, c)
   229  	return inst
   230  }
   231  
   232  func opCreateABx(op int, a int, bx int) uint32 {
   233  	var inst uint32 = 0
   234  	opSetOpCode(&inst, op)
   235  	opSetArgA(&inst, a)
   236  	opSetArgBx(&inst, bx)
   237  	return inst
   238  }
   239  
   240  func opCreateASbx(op int, a int, sbx int) uint32 {
   241  	var inst uint32 = 0
   242  	opSetOpCode(&inst, op)
   243  	opSetArgA(&inst, a)
   244  	opSetArgSbx(&inst, sbx)
   245  	return inst
   246  }
   247  
   248  const (
   249  	opBitRk      = 1 << (opSizeB - 1)
   250  	opMaxIndexRk = opBitRk - 1
   251  )
   252  
   253  func opIsK(value int) bool {
   254  	return bool((value & opBitRk) != 0)
   255  }
   256  
   257  func opIndexK(value int) int {
   258  	return value & ^opBitRk
   259  }
   260  
   261  func opRkAsk(value int) int {
   262  	return value | opBitRk
   263  }
   264  
   265  func opToString(inst uint32) string {
   266  	op := opGetOpCode(inst)
   267  	if op > opCodeMax {
   268  		return ""
   269  	}
   270  	prop := &(opProps[op])
   271  
   272  	arga := opGetArgA(inst)
   273  	argb := opGetArgB(inst)
   274  	argc := opGetArgC(inst)
   275  	argbx := opGetArgBx(inst)
   276  	argsbx := opGetArgSbx(inst)
   277  
   278  	buf := ""
   279  	switch prop.Type {
   280  	case opTypeABC:
   281  		buf = fmt.Sprintf("%s      |  %d, %d, %d", prop.Name, arga, argb, argc)
   282  	case opTypeABx:
   283  		buf = fmt.Sprintf("%s      |  %d, %d", prop.Name, arga, argbx)
   284  	case opTypeASbx:
   285  		buf = fmt.Sprintf("%s      |  %d, %d", prop.Name, arga, argsbx)
   286  	}
   287  
   288  	switch op {
   289  	case OP_MOVE:
   290  		buf += fmt.Sprintf("; R(%v) := R(%v)", arga, argb)
   291  	case OP_MOVEN:
   292  		buf += fmt.Sprintf("; R(%v) := R(%v); followed by %v MOVE ops", arga, argb, argc)
   293  	case OP_LOADK:
   294  		buf += fmt.Sprintf("; R(%v) := Kst(%v)", arga, argbx)
   295  	case OP_LOADBOOL:
   296  		buf += fmt.Sprintf("; R(%v) := (Bool)%v; if (%v) pc++", arga, argb, argc)
   297  	case OP_LOADNIL:
   298  		buf += fmt.Sprintf("; R(%v) := ... := R(%v) := nil", arga, argb)
   299  	case OP_GETUPVAL:
   300  		buf += fmt.Sprintf("; R(%v) := UpValue[%v]", arga, argb)
   301  	case OP_GETGLOBAL:
   302  		buf += fmt.Sprintf("; R(%v) := Gbl[Kst(%v)]", arga, argbx)
   303  	case OP_GETTABLE:
   304  		buf += fmt.Sprintf("; R(%v) := R(%v)[RK(%v)]", arga, argb, argc)
   305  	case OP_GETTABLEKS:
   306  		buf += fmt.Sprintf("; R(%v) := R(%v)[RK(%v)] ; RK(%v) is constant string", arga, argb, argc, argc)
   307  	case OP_SETGLOBAL:
   308  		buf += fmt.Sprintf("; Gbl[Kst(%v)] := R(%v)", argbx, arga)
   309  	case OP_SETUPVAL:
   310  		buf += fmt.Sprintf("; UpValue[%v] := R(%v)", argb, arga)
   311  	case OP_SETTABLE:
   312  		buf += fmt.Sprintf("; R(%v)[RK(%v)] := RK(%v)", arga, argb, argc)
   313  	case OP_SETTABLEKS:
   314  		buf += fmt.Sprintf("; R(%v)[RK(%v)] := RK(%v) ; RK(%v) is constant string", arga, argb, argc, argb)
   315  	case OP_NEWTABLE:
   316  		buf += fmt.Sprintf("; R(%v) := {} (size = BC)", arga)
   317  	case OP_SELF:
   318  		buf += fmt.Sprintf("; R(%v+1) := R(%v); R(%v) := R(%v)[RK(%v)]", arga, argb, arga, argb, argc)
   319  	case OP_ADD:
   320  		buf += fmt.Sprintf("; R(%v) := RK(%v) + RK(%v)", arga, argb, argc)
   321  	case OP_SUB:
   322  		buf += fmt.Sprintf("; R(%v) := RK(%v) - RK(%v)", arga, argb, argc)
   323  	case OP_MUL:
   324  		buf += fmt.Sprintf("; R(%v) := RK(%v) * RK(%v)", arga, argb, argc)
   325  	case OP_DIV:
   326  		buf += fmt.Sprintf("; R(%v) := RK(%v) / RK(%v)", arga, argb, argc)
   327  	case OP_MOD:
   328  		buf += fmt.Sprintf("; R(%v) := RK(%v) %% RK(%v)", arga, argb, argc)
   329  	case OP_POW:
   330  		buf += fmt.Sprintf("; R(%v) := RK(%v) ^ RK(%v)", arga, argb, argc)
   331  	case OP_UNM:
   332  		buf += fmt.Sprintf("; R(%v) := -R(%v)", arga, argb)
   333  	case OP_NOT:
   334  		buf += fmt.Sprintf("; R(%v) := not R(%v)", arga, argb)
   335  	case OP_LEN:
   336  		buf += fmt.Sprintf("; R(%v) := length of R(%v)", arga, argb)
   337  	case OP_CONCAT:
   338  		buf += fmt.Sprintf("; R(%v) := R(%v).. ... ..R(%v)", arga, argb, argc)
   339  	case OP_JMP:
   340  		buf += fmt.Sprintf("; pc+=%v", argsbx)
   341  	case OP_EQ:
   342  		buf += fmt.Sprintf("; if ((RK(%v) == RK(%v)) ~= %v) then pc++", argb, argc, arga)
   343  	case OP_LT:
   344  		buf += fmt.Sprintf("; if ((RK(%v) <  RK(%v)) ~= %v) then pc++", argb, argc, arga)
   345  	case OP_LE:
   346  		buf += fmt.Sprintf("; if ((RK(%v) <= RK(%v)) ~= %v) then pc++", argb, argc, arga)
   347  	case OP_TEST:
   348  		buf += fmt.Sprintf("; if not (R(%v) <=> %v) then pc++", arga, argc)
   349  	case OP_TESTSET:
   350  		buf += fmt.Sprintf("; if (R(%v) <=> %v) then R(%v) := R(%v) else pc++", argb, argc, arga, argb)
   351  	case OP_CALL:
   352  		buf += fmt.Sprintf("; R(%v) ... R(%v+%v-2) := R(%v)(R(%v+1) ... R(%v+%v-1))", arga, arga, argc, arga, arga, arga, argb)
   353  	case OP_TAILCALL:
   354  		buf += fmt.Sprintf("; return R(%v)(R(%v+1) ... R(%v+%v-1))", arga, arga, arga, argb)
   355  	case OP_RETURN:
   356  		buf += fmt.Sprintf("; return R(%v) ... R(%v+%v-2)", arga, arga, argb)
   357  	case OP_FORLOOP:
   358  		buf += fmt.Sprintf("; R(%v)+=R(%v+2); if R(%v) <?= R(%v+1) then { pc+=%v; R(%v+3)=R(%v) }", arga, arga, arga, arga, argsbx, arga, arga)
   359  	case OP_FORPREP:
   360  		buf += fmt.Sprintf("; R(%v)-=R(%v+2); pc+=%v", arga, arga, argsbx)
   361  	case OP_TFORLOOP:
   362  		buf += fmt.Sprintf("; R(%v+3) ... R(%v+3+%v) := R(%v)(R(%v+1) R(%v+2)); if R(%v+3) ~= nil then { pc++; R(%v+2)=R(%v+3); }", arga, arga, argc, arga, arga, arga, arga, arga, arga)
   363  	case OP_SETLIST:
   364  		buf += fmt.Sprintf("; R(%v)[(%v-1)*FPF+i] := R(%v+i) 1 <= i <= %v", arga, argc, arga, argb)
   365  	case OP_CLOSE:
   366  		buf += fmt.Sprintf("; close all variables in the stack up to (>=) R(%v)", arga)
   367  	case OP_CLOSURE:
   368  		buf += fmt.Sprintf("; R(%v) := closure(KPROTO[%v] R(%v) ... R(%v+n))", arga, argbx, arga, arga)
   369  	case OP_VARARG:
   370  		buf += fmt.Sprintf(";  R(%v) R(%v+1) ... R(%v+%v-1) = vararg", arga, arga, arga, argb)
   371  	case OP_NOP:
   372  		/* nothing to do */
   373  	}
   374  	return buf
   375  }